1. Field of the Invention
The present invention relates to a lens barrier device of an imaging apparatus such as a camcorder or a digital camera.
2. Description of the Related Art
A conventional lens barrier device has the following construction (See, for example, Japanese Patent Application No. 2008-333524 (Japanese Patent Application Laid-Open No. 2010-156732)).
In the following, this construction will be described with reference to FIG. 12. In the conventional example, to protect an imaging lens, four barrier blades in total, i.e., outer barrier blades 120a and 120b and inner barrier blades 130a and 130b, rotate around rotation shafts 112a and 112b provided on an external cover 110 and parallel to the optical axis of the imaging lens. As illustrated in FIG. 13, when the lens barrier device is in the open state, the outer barrier blade 120a and the inner barrier blade 130a, and the outer barrier blade 120b and the inner barrier blade 130b, respectively overlap each other in the optical axis direction. Due to this construction, the projected area as seen from the optical axis forward end side in the open state is reduced, thereby realizing a reduction in the imaging lens diameter of the imaging apparatus.
However, in the above conventional technique, the external cover 110 is assembled to the imaging apparatus main body in combination with another external cover and the like. Thus, there is generated in the external cover 110 deformation or the like due to the assembling. As a result, the rotation shafts 112a and 112b undergo deformation, the requisite drive force for the opening/closing operation increases, and a suitable opening/closing operation is hindered. On the other hand, an attempt to realize in the external cover 110 a configuration helping to prevent the deformation due to the assembling to the imaging apparatus main body results in a limitation to the configuration of the external cover situated in front of the imaging apparatus main body. This is not desirable since it leads to a restriction in terms of salability factor such as design.
In view of this, there is formed a lens barrier unit by additionally providing, between the external cover 110 and the outer barrier blades 120a and 120b of the conventional example, another member on which the rotation shafts 112a and 112b are formed. This construction is also generally adopted in a lens barrier device in which the lens barrier unit is fixed to an external cover. This enables suppressing deformation due to the assembling of the external cover. However, due to an increase in the number of components, there is involved an increase in the production cost of the imaging apparatus main body and in the size thereof in the optical axis direction due to the added components.